Add Mac OS 9 Platinum style to report

- Restyle report with Mac OS 9.2.2 Platinum theme
- Add Charcoal font for UI elements, Monaco for numeric data
- Custom window chrome with titlebars and close buttons
- Mac-style checkboxes, scrollbars, and tabs
- Tabbed interface for game/category summaries using 9-patch tabs
- Filter games by service with styled checkboxes
- Support custom tiled background via --background flag
- Add --assets flag for Platinum assets directory

Platinum assets from grassmunk's Platinum9 GTK2 theme:
https://github.com/grassmunk/Platinum9/

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Platinum/Others/bg-tiled.xpm

@@ -0,0 +1,15 @@
+/* XPM */
+static char * bg_tiled_xpm[] = {
+"8 8 4 1",
+" 	c None",
+".	c #DDDDDD",
+"+	c #CCCCCC",
+"@	c #EEEEEE",
+".+++++++",
+"+.@+++@+",
+"++.+++++",
+"@+++@+++",
+"++++++.+",
+"++@++.@+",
+"++++.+++",
+"@+++@+++"};